SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e52579457de737fdaca90953996d942e05d102513e5b068fe77378b8a57a5ef7' 
  AND token = 'Lifg+66rbyz/rD7GuO1t7bcXxxCNqKgkZz8Ad55ukPk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}